What Is ACFM?
Alternating Current Field Measurement (ACFM) is a non-destructive electromagnetic method for detecting and sizing surface-breaking cracks in metals. It often works through coatings or paint without the need for stripping.
Key Benefits
- Detects and measures both crack length and depth
- Works through coatings, reducing prep time
- Ideal for fatigue crack monitoring
- Provides encoded, auditable inspection data
How It Works
An alternating current is induced into the material surface, creating a known electromagnetic field. If a crack is present, the field is disturbed. A dual sensor array detects these disturbances, which are processed into quantitative defect data.
Applications
- Weld inspections: offshore structures, bridges, tanks, vessels
- Pipelines: surface crack detection without coating removal
- Structural steel: risers, derricks, and fatigue-critical components
